Irrigation systems are well-known and can be found in wide-spread use. Typical systems include at least one length of pipe having a number of sprinkler heads distributed so as to cover a desired pattern for watering. The pipe, or pipes in the case of a multiple-zone system, is usually buried underground, with the sprinkler heads rising above ground level at least during use. If, during the winter months, the frost level extends below the level of the pipe, water within the pipe can expand as the temperature approaches freezing and can damage the pipe or other components of the system. For at least this reason, it is important to “winterize” an irrigation system by draining a substantial portion of the water left in the system when not in use.
Conventional winterizing systems use compressed air to blow excess fluid from the interior of the sprinkler system. However, compressed air can damage underground appliances and fixtures such as sprinkler heads, hose connectors, zone valves, and water delivery lines. Compressed air can also flutter backflow prevention valve seals. This can damage the backflow prevention valve and cause it to fail. Systems with faulty backflow prevention valves are at risk of allowing water to siphon back into plumbing lines, which can contaminate drinking water.
An improved system is needed that will remove water and other fluids from irrigation lines to avoid damage from frost. Preferably, such a system would not require operation by a qualified service person, and would not be likely to damage components of the irrigation system.